Optimization of Turkey Berry (Solanum torvum) Powder Spice Blend by Means of D-optimal Design

Abstract

The objective of this study was optimization of turkey berry (Solanum torvum) spice blend/formulation using turkey berry powder (TBP), Ginger (Zingiber officinale) powder (GP) and Anchovy (Engraulis capensis) Powder (SP) adopting the D-optimal mixture design approach. A seventeen (17) experimental runs generated by response surface software was evaluated with total phenolic content (TPC), ferric reducing antioxidant power (FRAP) and ARONA as the responses (dependent variables). Results demonstrated that all three components (TBP, GP and AP) had effect on the antioxidant and sensory parameters of the turkey berry powder spice blend. Generally, increasing ginger powder component reduced the antioxidant and sensory properties while increasing turkey berry powder and anchovy powder components had positive effect of increasing the quality characteristics of the spice blend. Sensory evaluation of the aroma, taste and overall acceptability of the optimized spice blend were above an average score of seven (7) on a scale of nine (9). The optimum formulation obtained had Turkey Berry Powder (193.676 g), Ginger Powder (2.577 g) and Anchovy Powder (53.747 g) to achieve the expected responses: TPC (263.824 mg GAE/100 g fw), AROMA (7.55516) and FRAP [9.32421 (µmol TE (Trolox) g-1 fw)] with desirability index (DI) value of 0.614. Though not so high a DI, the results suggest the possibility of producing a spice blend from turkey berry with acceptable quality characteristics. More quality as well as shelf life assessments be carried out for possible commercialization of turkey berry powder spice blend.